When I'm fixing windows
Our house dates from the turn of the century and has been redeveloped several times, at some point it had metal "Crittall" windows installed. These were single glazed, and in poor state of repair so when we had rebuilding work done we had to find similar/matching designs and settled on some new metal windows called "heritage" windows from a company called "Duration Windows".
They looked great, almost perfectly matching the original design. They also had matching "window catches" internally, rather than your typical upvc style handles.
Window with one of the opening arms:
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| Picture showing the window latch, siamese cats assist. |
Unfortunately, just a few years later these started to fail one at a time, close inspection revealed that they had been manufactured with some cheap poor quality cast alloy.
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(one of) the broken hinge parts |
Naturally I contacted the supplier for assistance but was simply advised that: "oh we don't do those any more" apparently there were no remaining spare supplies I could get and neither were there any replacement options. Their suggested solution was to replace with new windows.
Yeah right.
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| This is one of the handles with the geared opening mechanism |
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Internal rack
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| The hinge parts, (with cracked gear) |
So. This was the problem that caused me to finally buy a 3D printer. I'd been planning on getting one for years, but had always put off the idea, partly to wait for technology to improve - I have a habit of being an 'early adopter' usually and frequently end up with fledgling or obsolete technology (in car mini-disc anyone?) - but also needing a definite project I could use one on... Now I had one!
My plan was to use the 3D printer to design, model and test newly designed catches. Then figure out how to get them made by someone.
I settled on a Bambu lab A1 mini, I decided it wasn't too expensive to be something I'd regret, but also I thought it was large enough for what I'd want it for.
I ran through *many* iterations, designs, and fine-tuning before I had a design I was happy with.
After several little projects to get familiar with FreeCAD and how I'd use it, I got cracking.
Firstly the overall shape was measured and modelled.
Then started to refine and shape to match the details.
Then marking the milled out sections onto the two split parts.
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| various 3d printed prototypes |
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| Finished prototype parts |
The plastic 3D printed designs I built actually worked when I installed one on a window!!
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| 3d printed catch installed |
But clearly I needed to get metal ones created for real life use.
When I first started this project I'd assumed I'd need to either work out how to cast my own using the 3D models as reference models, or get someone else to make them, but I've never actually successfully cast anything (yes I do have the kit in my garage to try!)
Inevitably the project languished for a while.... until after I'd used JLCPCB several times for my GPS project, I noticed and realised they had a 3D printing service. Given a design they can 3D print in metal or CNC mill models!
I'd previously used a different 3D print service for a project before I'd got a 3D printer so I was confident and comfortable with how easy it is to create and send off a design.
So, I ordered a selection of builds, metal 3D printed versions in a the different metal types they offered, and also a CNC milled aluminium version.
(I knew I'd need to get threads added, but decided to ignore that for these first tests)
When the familiar blue box arrived the results were superb, all worked but needed to decided and settle on a finish. The printed ones were either a matt or polished finish so would need to paint these, but I could get the CNC one anodized as black which is an excellent match. Much umm-ing and ahh-ing and decision was made, black anodised aluminium CNC milled for the bodies and a 3D printed inner gear.
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| a technical drawing with thread details |
Time to place the "big" order... clearly this isn't going to be cheap (the CNC version costs more than the 3D print) but in the big picture here, this cost is obviously nothing compared to a new set of windows - also I needed to add on details of the M3 threads needed by adding a technical drawing, a bit of fiddling with the FreeCAD drawing option and I had a PDF with the thread info added. Credit card hammered...
and a few weeks later.... another blue box. With 20 new window catches to fit!
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| Scattered CNC milled aluminium catch parts |
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| Assembed new metal window catch |
and as I've said a few times already, I'm just *astounded* this sort of thing is possible to do now, as a simple hobbyist - from idea, to design, to commercial quality finished project.
Just an aside... this wasn't an overnight solution and took me about 5 years from deciding to do something about the broken catches to having a finished CNC milled replacement in my hand!
